Conventional in-window air conditioners tend to be loud (often in the 50-60 dB range), large, and heavy. Installation of such an air conditioner within a window can be difficult due to its weight and bulk. Once installed, the air conditioner blocks visibility through the portion of the window occupied by the air conditioner. When occupied by an air conditioner, the window may also otherwise be non-functional; that is, while the air conditioner is installed, it may not be possible to safely open the window for fresh air. Further, air conditioners are typically made a standard size and have expandable spacers on one or both sides to allow the air conditioner to laterally fill a space created by opening the window to accommodate the air conditioner. Such spacers are typically poor insulators, allowing heat to enter the room being cooled by the air conditioner. Further, conventional in-window air conditioners tend to rely exclusively on a refrigeration cycle using a refrigerant, compressor, and expansion valve. Such an arrangement may not be efficient in certain temperature environments.